1. Field of the Invention
The present invention relates to a clutch module, especially for a motor vehicle.
More particularly, the invention relates to a clutch module of the type comprising an assembly of adjacent components of generally annular form coaxial with each other, among which are arranged, in succession, a cover plate, a diaphragm, a pressure plate coupled in rotation to the cover plate by fastening means for enabling the pressure plate to be displaced axially with respect to the cover plate, a friction disc for coupling the clutch module in rotation to a driven shaft, and a reaction plate fixed to the cover plate by fastening means arranged at the outer periphery of the module, of the type in which the friction disc includes at least one peripheral annular friction liner, which is interposed between radial friction surfaces, in facing relationship with each other of the pressure plate and reaction plate, wherein the diaphragm bears against the cover plate and the pressure plate in order to bias the latter axially in the direction corresponding to gripping of the friction liner, and of the type in which the reaction plate is mounted on a support plate which is fixed in rotation to a driving shaft, such as the crankshaft of an internal combustion engine, by means of a set of fastening members which are disposed radially inwardly with respect to the means fastening the reaction plate to the cover plate.
2. Description of the Prior Art
One example of such a clutch module is described and shown in FIG. 6 of the document FR-A-2 546 594. In that document, the means fastening the cover plate on the reaction plate, in order to form a unitary assembly in the form of a clutch module, consist of the axially orientated annular skirt, or lateral wall, which is at the outer periphery of the cover plate, and the free end of which is seamed radially inwardly around an external peripheral rib or bead of the pressure plate.
That arrangement does give satisfaction, but, for a given radial size, the friction disc is unable to be of a maximum size, because the reaction plate is a mirror image of the pressure plate and includes lugs at its outer periphery for coupling it in rotation to the pressure plate through resilient tongues, each of which is fixed at one of its ends to the lug of the reaction plate, and at its other end to the lug of the pressure plate. The presence of the tongues thus prevents the size of the friction disc from being increased in the radial direction.
In addition, rotation of the cover plate cannot be prevented in any positive way, such as with the aid of fastening screws.
Other, more complex, fastening means are proposed in the said document, for example in FIG. 2, in which it is proposed to make use of fastening screws in order simultaneously to fasten the cover plate on the reaction plate and to fasten the latter on the support plate. In that case, it is the presence of the heads of the screws that prevents the size of the friction disc from being increased radially.